#include <bits/stdc++.h>
using namespace std;
const int MAX = 10000000;
const long long MOD = 998244353;
struct mat{
  array<array<long long, 2>, 2> A;
  mat(){
    A = {{{1, 0}, {0, 1}}};
  }
  mat(long long a, long long b, long long c, long long d){
    A = {{{a, b}, {c, d}}};
  }
  array<long long, 2> &operator [](int k){
    return A[k];
  }
};
mat operator *(mat A, mat B){
  mat ans;
  for (int i = 0; i < 2; i++){
    for (int j = 0; j < 2; j++){
      ans[i][j] = (A[i][0] * B[0][j] + A[i][1] * B[1][j]) % MOD;
    }
  }
  return ans;
}
mat matpow(mat A, long long N){
  mat ans;
  while (N > 0){
    if (N % 2 == 1){
      ans = ans * A;
    }
    A = A * A;
    N /= 2;
  }
  return ans;
}
int main(){
  int T;
  cin >> T;
  vector<mat> left(MAX + 1);
  for (int i = 0; i < MAX; i++){
    left[i + 1] = mat(i * 2 + 2, i, 1, 0) * left[i];
  }
  vector<mat> right(MAX + 1);
  for (int i = 0; i < MAX; i++){
    right[i + 1] = right[i] * mat(i * 2 + 2, i + 1, 1, 0);
  }
  for (int i = 0; i < T; i++){
    long long n, m;
    cin >> n >> m;
    if (n > m){
      swap(n, m);
    }
    mat A(n * 2 + 1, n, 1, 0);
    mat ans = right[n] * matpow(A, m - n) * left[n];
    cout << ans[0][0] << endl;
  }
}